Ostomy adhesive

ABSTRACT

An adhesive composition adapted for use with an ostomy appliance consisting of a mixture of a hydrocolloid gum, a pressure sensitive adhesive, and a cohesive strengthening agent. The cohesive strengthening agent is either an inert natural or synthetic fibrous material, finely divided cellulose, a cross-linked dextran, a cross-linked carboxymethylcellulose, or a starch-acrylonitrile graft copolymer.

BACKGROUND OF THE INVENTION

Major abdominal surgery for a number of diseases involving differentparts of the gastro-intestinal and urinary tract can result in a patientbeing left with an abdominal stoma. The three most common types ofabdominal stoma are the colostomy, the ileostomy, and the ileal conduit.In the case of an ileostomy, ileal conduit, and many colostomyoperations, the patient is unable to control the passage of bodily wastematerial and must rely upon an appliance attached to their body tocollect this material.

Several systems have been employed in the past for this purpose.Colostomates normally employ a disposable appliance which is either aone-piece or two-piece unit. The term disposable refers to the fact thatthe pouch or bag portion of the unit can be disposed of after a singleuse. A closed end pouch sealed along all of its edges with only anopening for the stoma is suitable for this purpose. The two-piecedisposable unit consists of such a bag suspended from a reusablemounting ring that is supported by a belt. The one-piece disposable unitcan be a disposable bag having an adhesive face plate which is attacheddirectly to body as shown in U.S. Pat. No. 3,055,368, a disposable baghaving a mounting gasket which is supported by a belt and can include asealing ring of karaya and glycerol as shown in U.S. Pat. No. 3,302,647,or a disposable bag supported by a sealing ring of karaya and glycerol,an adhesive ring, and a belt as shown in U.S. Pat. No. 3,351,061.

Persons having an ileostomy or urinary stoma normally employ a permanent(i.e., reusable) system or a semi-permanent system. This refers to thefact that the waste collecting bag or pouch has a valve or other type ofclosure means at the bottom. This permits the unit to remain on the bodyfor several days. Again, these systems are available as either aone-piece or two-piece unit.

The one-piece reusable unit consists of a bag having a bottom valve orother closure means and a permanently bonded rubber or plasticfaceplate. The faceplate has a centrally located opening for the stomaand can be attached directly to the body by means of latex cement or adouble sided pressure sensitive adhesive disk. It is also common toadhesively attach the faceplate to a skin barrier which fits around thestoma rather than directly to the skin. For added security, a pressureplate having a belt attachment and a plastic or metal ring that fitsbetween the faceplate and the bag can be employed. After several daysthe adhesive bond between the faceplate and the body or skin barrierwill weaken and the unit will be removed. The unit is cleaned andresidual adhesive is removed from the faceplate so that it can bereapplied. Eventually, the entire unit except for the pressure platewill have to be discarded due to erosion or odor build-up in the bag.

One-piece semi-permanent units for use with an ileostomy stoma having akaraya sealing ring bonded to the faceplate are commercially available.

The two-piece reusable unit consists of a rubber flange having anopening for the stoma which is adhesively attached directly to the bodyor to a skin barrier and a separate bag having a bottom valve or otherclosure means which fits tightly over the flange.

Chen in U.S. Pat. No. 3,339,546 describes a bandage having an adhesivelayer consisting of a mixture of gelatin, pectin, sodiumcarboxymethylcellulose, and polyisobutylene and a water insolublepolyethylene film. This bandage is currently employed as a skin barrierby ostomates and is also available with a permanently attached flange.

Other commercially available skin barriers contain a cloth mesh layer orpolyethylene web sandwiched between two adhesive layers. The adhesivelayers comprise a conventional pressure sensitive adhesive and ahydrocolloid.

Further attempts have been made to develop ostomy sealing washers ofmaterials other than the karaya-glycerol gel described by Marsan in U.S.Pat. No. 3,302,647. For example, Pratt in U.S. Pat. No. 3,612,053describes an ostomy sealing washer formed from an oil-extended blockcopolymer having a water activatable adhesive on one surface, Marsan inU.S. Pat. Nos. 3,712,304 and 3,799,166 describes an ostomy seal madefrom starch and gelatinized starch cross-linked with glyoxal, Marsan inU.S. Pat. No. 3,878,847 describes a thin membrane that contacts thestoma, Marsan in U.S. Pat. No. 3,908,658 describes an ostomy seal formedfrom a gel of mineral oil, styreneisobutylene copolymer and anethylene-vinyl acetate copolymer, and Kross in U.S. Pat. Nos. 3,877,431and 3,980,084 describes ostomy seals formed from polymeric materials.

SUMMARY OF THE INVENTION

This invention is directed to an improved adhesive composition which isparticularly adapted to be used in the ostomy field.

The adhesive composition consists of a mixture of a hydrocolloid gum, apressure sensitive adhesive, and an agent which increases the cohesivestrength of the composition. The cohesive strengthening agent is eitheran inert natural or synthetic fibrous material, a finely dividedpurified wood cellulose, a cross-linked dextran, a cross-linkedcarboxymethylcellulose, or a starch-acrylonitrile graft copolymer.

DETAILED DESCRIPTION

For an adhesive composition to be useful in the ostomy field it mustpossess several attributes. Since the composition is contacting the bodyaround the stoma it must not contain ingredients which will irritatethis already sensitive area of skin.

When the adhesive composition is employed as a skin barrier it must becapable of supporting the weight or the attached one-piece or two-pieceappliance and yet permit removal of the appliance for disposal orcleaning without also removing the barrier from the skin. It isdesirable from both an economic and medical point of view to have a skinbarrier which can remain in place for a week or longer.

The adhesive composition whether used as a skin barrier, formed intosealing rings, or applied directly onto the faceplate of a one-pieceappliance or the flange element of a two-piece appliance must resisterosion caused by the leakage of effluent from the stoma. Particularly,with a urinary stoma, ileostomy, or "wet" colostomy the effluent ishighly caustic and can erode the adhesive causing failure of the bandageand the partially dissolved adhesive material can flow into the bagblocking the bottom drain valve. Also, erosion of the adhesive permitsthis corrosive effluent to contact the skin causing serious irritation.

As discussed above, previous attempts to develop an adhesive compositionhaving these properties included the incorporation of varioushydrocolloid gum materials into the adhesive composition. It was feltthat these hydrocolloid materials would absorb moisture such asperspiration and provide wet adhesion for the composition. It was alsoknown that the cohesive strength of the adhesive composition was animportant factor. This strengthening was provided, as discussed above,by the presence of an outer polymeric film or a cloth mesh orpolyethylene web sandwiched within the adhesive composition.

It has now been discovered that an adhesive composition having theproperties of long duration of adhesion as well as cohesive strength canbe obtained by employing certain hydrocolloid gums, pressure sensitiveadhesives, and a cohesive strengthening agent. It has been found thatcertain hydrocolloid gums while possessing the ability to absorb surfacemoisture such as perspiration, in fact, are not suitable for use in thecomposition since they swell too rapidly and turn into a soft gelatinousmass. This swelling and loss of consistency causes the adhesivecomposition to erode the disintegrate.

Thus, the hydrocolloid gum component of the adhesive composition shouldhave a large capacity to absorb moisture, should provide wet adhesion,and should also hydrate and swell at a relatively slow rate so as not tocause disintegration of the adhesive composition. Guar gum, locust beangum, and mixtures thereof have been found to be suitable with guar beingpreferred and such gums can be present at from about 15% to about 40% byweight of the adhesive composition.

An additional gum substance having soothing or healing properties can beincluded within the adhesive composition. Pectin, gum karaya, andmixtures thereof have been found to be suitable with pectin beingpreferred and can be present at from 0% to about 25% by weight of theadhesive composition provided that the total amount of gums within theadhesive composition is from about 25% to about 55% by weight.

The pressure sensitive adhesive component of the composition providesdry adhesion and holds the entire composition together. Various naturalor synthetic viscous substances either possessing dry tack by themselvesor developing such tack upon the addition of a plasticizer such asnatural rubber, silicone rubber, acrylonitrile rubber, polyurethanerubber, polyisobutylenes, etc., are suitable for this purpose. Lowmolecular weight polyisobutylenes having a viscosity average molecularweight of from about 36,000 to about 58,000 (Flory) are preferred. Suchpolyisobutylenes are commercially available under the trademark Vistanexfrom Exxon Co. as grades LM-MS and LM-MH. Optionally, in order toincrease the elasticity and tear resistance of the adhesive compositionelastomeric polymers such as medium molecular weight polyisobutyleneshaving a viscosity average molecular weight of from about 1,150,000 to1,600,000 (Florey) or butyl rubber which is a copolymer of isobutylenewith a minor amount of isoprene having a viscosity average molecularweight of from about 300,000 to about 450,000 (Florey) can be added.Butyl rubber having a viscosity average molecular weight of about425,000 (commercially available as grade 077) is preferred. Theelastomer can be added in amounts of up to about 30% by weight of thepressure sensitive adhesive. The pressure sensitive adhesive and theoptionally added elastomer together can be from about 40% to about 60%by weight of the adhesive composition. Preferably, the low molecularweight polyisobutylene pressure sensitive adhesive and the highermolecular weight butyl rubber elastomer are employed in a ratio of fromabout 3 to 1 to about 5 to 1 on a weight basis, 4 to 1 being mostpreferred, and the combination is present at from about 45% to about 55%by weight of the total adhesive composition.

The cohesive strengthening agent functions in the adhesive compositionby increasing resistance to tearing, decreasing the tendency to erodeand disintegrate by absorbing moisture and thus controlling the swellingof the hydrocolloid gums, and controlling oozing. Oozing is due to thecold-flow of the polyisobutylene and occurs when the adhesivecomposition is stored for several months. Oozing is increased when theadhesive composition is heated or gamma irradiated.

Materials suitable for use as the cohesive strengthening agent includenatural or synthetic inert fibrous materials such as cotton and Dacron,finely divided cellulose materials including purified wood cellulosesuch as that available commercially under the trademark Solka-Floc andmicrocrystalline cellulose such as that available commercially under thename Avicel, finely divided substantially water insoluble cross-linkeddextran such as that available commercially under the trademarkSephadex, finely divided substantially water insoluble cross-linkedsodium carboxymethylcellulose such as that available commercially underthe trademark Aqualon or that described in U.S. Pat. No. 3,589,364 andavailable commercially from The Buckeye Cellulose Corp., and a finelydivided substantially water insoluble starch-acrylonitrile graftcopolymer such as that described in U.S. Pat. No. 3,661,815 andcommercially available from the Grain Processing Corp. The fibrousmaterial is employed at from about 2% to about 12% by weight of theadhesive composition and the cellulose, cross-linked dextran,cross-linked sodium carboxymethylcellulose, or starch-acrylonitrilegraft copolymer are employed at from about 10% to about 30% by weight ofthe adhesive composition. Cotton and purified wood cellulose are thepreferred cohesive strengtheners.

Small amounts, i.e., less than 5% by weight of the adhesive composition,of other ingredients can be also included. For example, a plasticizersuch as mineral oil, an antioxidant such as butylated hydroxyanisole, adeodorant or perfume agent.

The adhesive composition is prepared by forming a homogeneous dispersionof the pressure sensitive adhesive component and the elastomer with aheavy duty mixer, e.g. a kneader mixer or sigma blade mixer. Thehydrocolloid gums, cohesive strengthening agent, and any other optionalingredients are added and mixing is continued until a homogeneous doughis formed. Alternatively, the elastomer is first broken down by mixingfor several minutes, a portion of the pressure sensitive adhesive andother ingredients are added and mixing continued until a homogeneousmass is formed. The balance of the pressure sensitive adhesive is thenadded and the mixing continued until a homogeneous dough is formed. Thisdough can then be extruded and shaped as desired.

If desired a thin continuous or discontinuous film of polymeric materialsuch as polyethylene, polyurethane, PVC, PVDC, etc. can be laminatedonto one side of the adhesive material as taught in U.S. Pat. No.3,339,546. The film is present at from about 1.0 to about 10.0 mils.thickness and will, of course, increase the cohesiveness of the adhesivecomposition. The exposed side of the adhesive composition or both sidesif the film is omitted is covered with a piece of silicone coatedrelease paper. A flange can be attached directly to this skin barrierfor use by those ostomates who prefer a two-piece system.

The improved adhesive composition can also be shaped so as to be used asan ostomy sealing washer.

The improved adhesive composition either with or without the outerpolymeric film layer can also be bonded to the faceplate or mountinggasket of an ostomy bag as in U.S. Pat. Nos. 3,302,647 and 3,351,061 orthe improved adhesive composition without the outer polymeric layer canbe applied directly to as ostomy bag as in U.S. Pat. No. 3,055,368.

While the adhesive composition of this invention has been particularlydescribed for use in the ostomy field, it is also useful for relatedmedicinal purposes. For example, the adhesive composition can beemployed to affix various devices to the body such as a catheter, anelectronic probe, a wound drainage system as taught in U.S. Pat. Nos.3,568,675 to Harvey and 3,954,105 to Nordby or can be applied directlyto a subcutaneous ulcer.

The adhesive composition of this invention can be sterilized by means ofgamma radiation.

Preferred adhesive compositions within the scope of this inventioncomprise on a weight basis from about 2% to about 12% cotton or fromabout 10 to about 30% finely divided purified wood cellulose as thecohesive strengthening agent; from about 15% to about 40% guar gum; fromabout 0% to about 25% pectin provided that when the cohesivestrengthening agent is cotton the guar gum and pectin combined are fromabout 35% to about 55% and when the cohesive strengthening agent is woodcellulose the guar gum and pectin combined are from about 20% to about45%; and from about 45% to about 55% of the mixture of low molecularweight polyisobutylene and butyl rubber wherein the ratio of lowmolecular weight polyisobutylene to butyl rubber is about 4 to 1 on aweight basis.

The following examples are illustrative of the invention. Other suitableadhesive composition can be obtained by minor variations in the amountsof ingredients employed.

EXAMPLE 1

This example is directed to preparing an adhesive having the followingcomposition:

    ______________________________________                                        Ingredient            Percent by weight                                       ______________________________________                                        Polyisobutylene of a                                                          viscosity average                                                             molecular weight (Flory)                                                      of 36,000 to 45,000                                                           (Vistanex LM-MS of Exxon)                                                                           40                                                      Butyl rubber of a                                                             viscosity average                                                             molecular weight (Flory)                                                      of 425,000 (Exxon                                                             grade 077)            10                                                      Guar gum of high grade                                                        extra fine powder                                                             (Jaguar A-40-F of                                                             Stein Hall Co.)       30                                                      Finely divided purified                                                       wood cellulose                                                                (Solka Floc BW-100 of                                                         Brown Co.)            20                                                                            100                                                     ______________________________________                                    

2 kg. of butyl rubber is broken down by mixing in a kneader mixer fortwo to five minutes. 4 kg. of the low molecular weight polyisobutyleneis added and mixed with the butyl rubber for two to five minutes. 6 kg.of guar gum and 4 kg. of the finely divided purified wood cellulose arecombined in a powder mixer and the resulting powder is added to thepolyisobutylene-butyl rubber mixture. Mixing of the ingredients iscontinued until a homogeneous mass is formed with the polyisobutyleneand butyl rubber completely interdispersed (about 10 to 20 minutes). Theremaining 4 kg. of the low molecular weight polyisobutylene is added andmixing is continued until a homogeneous dough is formed (about 10 to 20minutes).

This dough mass while hot and soft is extruded and flattened. A sheet ofpolyethylene of 1.5 mils thickness is pressed over one side and siliconecoated release paper on the other. The resultant mat is cut into thedesired shape.

EXAMPLES 2-26

Following the procedure of example 1 but employing the followingingredients on a percent weight basis other adhesive compositions withinthe scope of the invention are prepared.

    __________________________________________________________________________       Polyisobutylenes                                                              (4:1 ratio of            Purified       Cross-linked                          Vistenex LM-MS           wood  Microcrystalline                                                                       dextran                               and butyl rubber                                                                       Guar                                                                             Locust       cellulose                                                                           cellulose                                                                              (Sepadex                           Ex.                                                                              grade 077)                                                                             gum                                                                              bean gum                                                                           Pectin                                                                            Karaya                                                                            (Solka-floc)                                                                        (Avicel) CM-C50)                            __________________________________________________________________________    2  50%      20%                                                                              --   --  --  30%   --       --                                 3  50%      40%                                                                              --   --  --  10%   --       --                                 4  50%      35%                                                                              --   --  --  15%   --       --                                 5  45%      35%                                                                              --   --  --  20%   --       --                                 6  50%      20%                                                                              --   10% --  20%   --       --                                 7  40%      30%                                                                              --   20% --  10%   --       --                                 8  50%      15%                                                                              --   15% --  20%   --       --                                 9  50%      25%                                                                              --   10% --  15%   --       --                                 10 40%      25%                                                                              --   --  25% 10%   --       --                                 11 50%      35%                                                                              --   --  --  --    --       15%                                12 45%      35%                                                                              --   --  --  --    --       20%                                13 45%      35%                                                                              --   --  --  --    20%      --                                 14 50%      -- 30%  --  --  20%   --       --                                 15 50%      -- 20%  --  --  30%   --       --                                 16 50%      20%                                                                              10%  --  --  20%   --       --                                 17 40%      20%                                                                              --   15% 15% 10%   --       --                                 18 60%      25%                                                                              --   --  --  15%   --       --                                 19 45%      -- 35%  --  --  20%   --       --                                 20 50%      -- 20%  10% --  20%   --       --                                 __________________________________________________________________________       Polyisobutylenes         Cross-linked                                                                              Starch-acrylonitrile                     (4:1 ratio of            sodium carboxymethyl-                                                                     graft copolymer                          Vistanex LM-MS           cellulose (Hercules                                                                       (Grain Processing                        and butyl rubber                                                                       Guar                                                                             Locust       Aqualon R or Buckeye                                                                      Corp. Polymer                         Ex.                                                                              grade 077)                                                                             gum                                                                              bean gum                                                                           Pectin                                                                            Karaya                                                                            Cellulose Corp. CLD)                                                                      35-A-100)                             __________________________________________________________________________    21 50%      35%                                                                              --   --  --  15%         --                                    22 45%      35%                                                                              --   --  --  20%         --                                    23 40%      25%                                                                              --   25% --  10%         --                                    24 50%      35%                                                                              --   --  --  --          15%                                   25 45%      35%                                                                              --   --  --  --          20%                                   26 40%      -- 25%  25% --  --          10%                                   __________________________________________________________________________

EXAMPLE 27

This example is directed to preparing an adhesive having the followingcomposition.

    ______________________________________                                        Ingredient              Percent by weight                                     ______________________________________                                        Polyisobutylene of a viscosity average                                        molecular weight of 36,000 to 45,000 (Flory)                                  (Vistanex LM-MS of Exxon)                                                                             38.0                                                  Butyl rubber of a viscosity average                                           molecular weight (Flory) of 425,000                                           (Exxon Grade 077)       9.5                                                   Guar gum of high grade,                                                       extra fine powder                                                             (Jaguar A-40-F of                                                             Stein Hall Co.)         28.5                                                  Pectin                  19.0                                                  Cotton                  5.0                                                                           100.0                                                 ______________________________________                                    

1.9 kg. of butyl rubber is broken down by mixing in a kneader mixer fortwo to five minutes. 3.8 kg. of the low molecular weight polyisobutyleneis added and mixed with the butyl rubber for two to five minutes. 5.7kg. of guar gum and 3.8 kg. of pectin are combined in a powder mixer andthe resulting powder is added to the low molecular weightpolyisobutylene-butyl rubber mixture followed by the addition of 1 kg.of cotton. Mixing of the ingredients is continued until a homogeneousmass is formed with the polyisobutylene and butyl rubber completelyinterdispersed (about 10 to 20 minutes). The remaining 3.8 kg. of lowmolecular weight polyisobutylene is added and mixing continued until ahomogeneous dough is formed (about 10 to 20 minutes).

This dough mass can then be extruded and laminated with a sheet ofpolyethylene as set forth in Example 1.

EXAMPLES 28 TO 36

Following the procedure of example 27 but employing the followingingredients on a percent weight basis other adhesive compositions withinthe scope of the invention are prepared.

    ______________________________________                                             Polyisobutylene                                                               (4:1 ratio of                                                                 Vistenex                                                                      LM-MS                                                                         and butyl                                                                     rubber      Guar   Locust                                                Ex.  grade 077)  gum    bean gum                                                                             Pectin                                                                              Karaya                                                                              Cotton                             ______________________________________                                        28   50%         20%    --     20%   --    10%                                29    47.5%      --      28.5% 19%   --     5%                                30    47.5%       28.5% --     --    19%    5%                                31   50%         30%    --     10%   --    10%                                32   55%         23%    10%    --    --    12%                                33   50%         25%    --     10%   10%    5%                                34   60%         20%    --      8%   --    12%                                35   40%         34%    --     24%   --     2%                                36   50%         30%    --     10%   --    10%                                ______________________________________                                    

What is claimed is:
 1. An adhesive composition for medicinal purposesconsisting essentially of a substantially homogenous mixture on apercent weight basis of from about 15% to about 40% of guar gum, locustbean gum, or mixtures thereof; from 0% to about 25% of pectin, gumkaraya, or mixtures thereof provided that the total amount of guar gum,locust bean gum, gum karaya and pectin is from about 20% to about 55%;from about 40% to about 60% of a mixture of a low molecular weightpolyisobutylene having a viscosity average molecular weight of fromabout 36,000 to about 58,000 on the Flory scale and butyl rubber havinga viscosity average molecular weight of from about 300,000 to about450,000 on the Flory scale, said polyisobutylene and said butyl rubbercombined in a ratio of from about 3 to 1 to about 5 to 1 on a weightbasis; and as a cohesive strengthening agent from about 2% to about 12%of an inert natural or synthetic fibrous material or from about 10% toabout 30% of a finely divided cellulose, a finely divided substantiallywater insoluble cross-linked dextran, a finely divided substantiallywater insoluble cross-linked sodium carboxymethylcellulose, or a finelydivided substantially water insoluble starch-acrylonitrile graftpolymer.
 2. The composition of claim 1 wherein the cohesivestrengthening agent is from about 2% to about 12% cotton.
 3. Thecomposition of claim 2 comprising from about 15% to about 40% guar gum;from 0% to 25% pectin provided that the total amount of guar gum andpectin is from about 35% to about 55%; and from about 45% to about 55%of the mixture of said low molecular weight polyisobutylene and saidbutyl rubber wherein the ratio of low molecular weight polyisobutyleneto butyl rubber is about 4 to 1 on a weight basis.
 4. The composition ofclaim 3 comprising about 5% cottom, about 28.5% guar gum, about 19%pectin, about 47.5% of a 4 to 1 mixture of polyisobutylene of aviscosity average molecular weight of about 36,000 to about 45,000 onthe Flory scale and butyl rubber of a viscosity average molecular weightof about 425,000 on the Flory scale.
 5. The composition of claim 1wherein the cohesive strengthening agent is from about 10% to about 30%finely divided purified wood cellulose.
 6. The composition of claim 5comprising from about 15% to about 40% guar gum; from 0% to 25% pectinprovided that the total amount of guar gum and pectin is from about 20%to 45%; and from about 45% to about 55% of said mixture of low molecularweight polyisobutylene and said butyl rubber wherein the ratio of lowmolecular weight polyisobutylene to butyl rubber is about 4 to 1 on aweight basis.
 7. The composition of claim 6 comprising about 20% finelydivided purified wood cellulose, about 30% guar gum, and about 50% of a4 to 1 mixture of polyisobutylene of a viscosity average molecularweight of about 36,000 to about 45,000 on the Flory scale and butylrubber of a viscosity average molecular weight or about 425,000 on theFlory scale.